rdoc of exit and exit!

Hello,

> *     exit(integer=0)
> *     Kernel::exit(integer=0)
> *     Process::exit(integer=0)
> *     Process.exit!(fixnum=-1)

The default arguments of exit and exit! are 0 and 1 in
rdoc,
but I think there are true and false now.


-- 
Kazuhiro NISHIYAMA